Self-propelled tamping roller



June 6, 1950 c. F. GREINER ETAL SELF-PROPELLED TAMPING ROLLER 7Sheets-Sheet 1 Filed June 4, 1945 Junefi, 1950 c. F; GREINER Elf-ml.

SELF-PROPELLED TAMPING ROLLER 7 Sheets-Sheet 2 Filed June 4, 1945 C. F.GREINER ETAL SELF-PROPELLED TAMPING ROLLER June 6, 1950 '7 Sheets-Sheet3 Filed June 4, 1945 7 Sheets-Sheet 4 June 6, 1950 c. F. GREINER ETALSELF-PROPELLED TAMPING ROLLER Filed- June 4, 1 945 I June 6, 1950 I C.F. GREINER ET'AL SELF-PROPELLED TAMPING ROLLER 'TSheets-Sheet 5 FiledJune 4, 1945 June 6, 1950 C. F. GREINER 'EIAL 7 SELF-PROPELLED TAMPINGROLLER Filed June 4, 1945 7 Sheets-Sheet 6 June 6,. 1950 c. F. GREINERETAL SELF-PROPELLED TAMPING ROLLER '7 Sheets-Sheet 7 Filed June 4, 1945grime/mm Sew W Patented June 6, 1950 CarlF'. Gr'eifier and JohnF.'-Harrison-, Sp?

011w, alssignors to The Buffalo-Springfield; Roller Springfield, Ohio, acorporation of Application June 4, 1945', Serial N 0. 597,393

(Cl-.7 B ie-50 2e Claims. 1'

invention is a; novef improvement in self-'- prop'eiling tampingrollers, and the p cip'al" 01oeet tirereofi is to provide a tam-pingr'oli'er having a traction-unit and a trailing unit; each unit catrying" paraliel tamp'in'g rolls provided with sheep'sdoot elements; eachsaid roH being mounted for independent tilting movement on a iiozizon'iiai axis disposed parallel with them gitudinal axis of the tampingroller, the units be ing pivotaIIy connected together a manner asprovidea mini-mum wheelbase for the winning roller, and to provide aminim-um tut-m mg radius rendering it pos'sible to turn the temp ingroller around for the return trip instead of having to reversethe driveas in conventional tamfing rollers, the convenience aohiev'c? by turningthe machinearo'u-nd after travei' the one direction being ofconsiderable vaiue since Slilh arrangement renofers it possible to usein the tam'pi'rig roller a conventional truck or tractor typetransmission with complete satisfaction; owing to" the fact that theturning aroundor the tamping' roller" Wi'lT cause the roller" to travelin the forward gear at all times; however, a reversible transmission maybe used: in place of the conventional truck or tractor type transmissionwith complete satisfaction;

Our present invention is ani mpr'ovement' upon the tampi ng roller shownin U. S. Letters- Patent N01 212261182 issued Decemloer 24 940 toMatthew S. Rioss wh'ieh the tam-ping ro'H'er' is pro-- vi'ded with anarticulated frame; and the pres ent invention is also an" improvementupon" the tampi'ng roIIe'r shown in our co-p'endii1g apnoeation,oer-arm; 555,098, filed September 2-1, 944, now Letters Patent- No.2"-,437 ,5-2 dated March 91 1 9483 Other minor objects of the inventionw-ili be hereinafter setfbrth. I

We will expia'h the" invention with reference to the accompanyingdrawings which show severaT ractical' embodiments thereof; to enableothers familiar with the art to adopt and." use the same; anci willsummarize in the claims the novel features of" construction; and n0VeI=combination of parts; for which protection is desired-i In saiddrawingsz Figure 1 is a side elevation of onef'orm of temp i ng rollerembodying our invention.

Fig. 2 is a top piarr View, partly in section; of theftamping rol-Iershowni-nFig. V s

Fig. 3 a hori'zontalfisection on the line- 33; Fig. I, through one'ofthe drive rolls of the'trac ti'ori of thetampi'ng roiie'r shown inFig. 1

2 showing the driving connections for the roll; and the pivots; oi thesale frame carrying: the drive roil Fig. 4; is arr entarge'di verticalsection through the pivotal eonneetiorr oi the traction and traitingiunitsof tamping shown: in. Fig, 12.

Fig... 5 is a; side elevation of a modified: term: of tamping roller;embodying our invention.

Fig; 6 a; top plan view partly in section:- of the tamping:roiler'showna in 5 Fig; 7% an enlarged; vertioak section th rouglr thepivotah conneotiom between the traction! and trailing units oi: the:vtampirrg, rolier' shown" in Fi 5.

Figs 8: is: a. side elevatiorr ofi a further modified form at tamping;roile'r embodying our invention.

Figs 9 is at top plan View partly section of the tamping roller shownin- Figs, 9a is an enlarge detail" section through the pivots ofith-ecenter su-bir'am-eof. the traiting unite Fig. 10 is a side elevation oithe: tractionunit showni-riJE ig. 1 equipped with a gear drive insteadoat a chain. drives Fig. 11: is a: horizontai section on the line Iii-4|-,6 Figs 10. s

As shown in Figs; 1-4,; the tamping roller com,- prises a traction unitA. carrying. the drive rolls, the motor and: transmission; also the pperators cabhousi ngthe-necessary controls andg a trailinguni-t B; carryingthe trailing rolls, said units A andiB being connectedtogether b-yapivotal connection C whereby the. units A, and B-- may be anticulatedfor steering purposes, the pivotal eonnection. permitting the turning,of the: trailing unit B'with-resbect to the traction unit A on thhoriz'ont'al'v and vertical axes.

The traction unit A comprises a. chassis in which is mounted? a motor I,driving through speed-change gearing" contained" in; casing 2' adifferential housed-I in casing, 3i,v said di'fie'rentfal beir'i'gjof'Ir-type; and units I", 2 and 3"' being? dispo'secfin' alignment; withthe" difierenti'aldisposed adjacent the" rear end or the tractionchassis. The motor l and parts" 2' and 3? may be covered by a Hood 4;terminating at the rear iii a. cab 5' ina mannersimilar to an ordinarytruck), Said cab 5 housing the drivers' seat 6 and the necessary motor'and steering controls (not shown) Extending'from" each side of thetraction. Chassis are spaced parallel" arms 1-8; the rear" arms 8' beingdisposed in'advance of the T-sheiift's 3a of? differential 3'. In eachpair; of arms: 1-8 is journaled afreotang'ular sub fraiiie 9* pivoted asat 921' on its center Ii'ne' on a Horizontal" axis parallel with thelongitudinal axis of the chassis, whereby each sub frame 9 is permittedto swing freely on its axes 9a. Mounted on an axle IE journaled in eachsub frame 9 is drive r011 carrying tamping elements I2 preferably of thesheeps-foot or any other desired type, arranged in any desired mannerand extending radially of the roll II.

By the above construction the rolls II, which are the drive rollsjournaled in pivoted sub frames e, are thus permitted to pivotindependently on horizontal axes 9a, so that in traversing the earth orground each individual roll II may adjust itself to suit the contour ofthe underlying round.

The means for driving the drive rolls II from differential 3 ispreferably but not necessarily substantially the same as disclosed inour co pending application Serial No. 555,093, (Patent 2,437,524) abovementioned, the drive being shown more particularly in Fig. 3. The driverolls I I including integral hubs I Ia are freely rotatably mounted uponthe axles In, the outer ends of the hubs providing suitable means toprevent axial movement of said rolls II on axles Iii. On the outer endof each drive roll II is a drive sprocket I3. On each sub frame 9opposite the sprocket I3 is a bracket IA adapted to swing with the subframe, said bracket being bifurcated and a shaft I5 is rotatablyjournaled in the bifurcations, as shown in Fig. 3, shaft I5 carrying asprocket I6 opposite its related sprocket I3; and a chain I'I runsaround each pair of sprockets I3 and I6.

The inner end of shaft I5 carries a universal joint I8; and the outerend of the adjacent differential shaft 30, carries a universal joint I9(Fig. 3) a shaft section 25 connecting the opposed members of theuniversal joints I8-I9, shaft 29 being preferably splined therein asshown in Fig. 3 so as to permit elongation or contraction of the shaftassembly 3a, I9, 20, I8, l5 as the related subframe 9 pivots on its axesSet. By mounting the sprocket IE on the subframe 9 it is obvious that,as the sub-frame pivots, the relation be- P1? tween the sprockets I3 andI6 remains constant, and the sprockets remain at all times in the sameplane; and hence swinging of the sub-frames 9 does not in any way affectthe driving connections of the drive rolls II since the splinedconnections between shafts and the universal joints I8, I9 allows forlengthening and shortening of the drive for the rolls II.

The trailing unit B comprises a rectangular frame 2I with laterallyprojecting pairs of arms 22, 23 at each side, in which are pivotallymounted subframes 24 of substantially similar size and shape as thesub-frames 9, said sub-frames being pivoted on horizontal pivots 240. ateach end in the arms 22, 23. In each sub-frame 24 is mounted a tampingroll 25 freely rotatably mounted upon an axle 26, each roll 25 beingprovided with tamping elements 21 similar to the tamping elements I2 ofthe drive rolls II. Preferably the rolls 25 are of the same diameter andwidth as the drive rolls II. Pivots 24a are preferably disposed the samedistance from the longi tudinal axis of the tamping roller as the pivots9a of the sub-frames Q of the traction unit A, so that thetamping rolls25 carried by the subframes 2t of trailing unit B will substantiallyfollow the drive rolls II of the traction unit A. By the aboveconstruction the tamping rolls 25 for trailing unit B are permitted toswing individual- 1y on horizontal axes in their sub-frames 24 so as tofollow the contour of the underlying ground.

The pivotal connection C between the tractor unit A and trailing unit Bis shown more particularly in Fig. 4, the same comprising a verticallydisposed king pin 23 rigidly mounted centrally upon the rear end of thechassis of the traction unit A, as shown, preferably by means of abracket 29, said king pin 28 having a cap plate 30 removably secured toits upper end by means of bolts 3| (Figure 4).

Pivotally mounted upon king pin 28 is the hub 32 of a horizontal drawbar33, which hub is confined on the king pin between the bracket 29 and thecap plate 3t. Drawbar 33 carries a fixed bolt 34 (Fig. 4) disposedaxially thereof extending from its rear end on which bolt 34 ispivotally mounted for rotation on a horizontal axis a drawbar terminal35 maintained on bolt 34 by a nut 36, a bushing 3'! being preferablydisposed around the bolt 3d. Thus the terminal member 35 is permitted toswivel on a horizontal axis on bolt 34. The rear end of terminal member35 is rigidly secured in any desired manner to the center of the frontend of the trailing unit B. By the above construction, the trailing unitB is permitted to swivel as a unit on both vertical and horizontal axeswith respect to the traction unit A.

In order to effect steering of the tamping roller, hydraulic means arepreferably provided, the same consisting of 9, depending bracket 33 onthe drawbar 33 to which is pivoted, as at 39a, one end of adouble-acting hydraulic cylinder 39 disposed substantially horizontallybetween the units A and B, said hydraulic cylinder housing a pistoncarrying a rod 40 the outer end of which is pivotally connected as at 4!to a bracket 42 (Fig. 2) secured to the rear end of the chassis of thetraction unit A adjacent one outer side thereof. Cylinder 39 is providedwith inlet and outlet pipes (not shown) connected in a pressure fluidcircuit whereby fluid may be admitted into either end of cylinder 39 toshift the piston and its rod 40 to swing the units A and B on the kingpin 23 thus effecting steering. The use of hydraulic steering cylinderssuch as 39, and their fluid circuits, is well known in the roller art;and, therefore, needs no detailed description herein The arrangement ofunits A and B and pivotal connections 0 provides a tamping roller havinga much shorter wheel base than those heretofore constructed, with theresult that the tamping roller will have a much shorter turning radius,thus making it practicable and possible to turn the tamping rolleraround for the return trip instead of having to reverse the drive as inthe conventional tamping rollers. Tamping rollers usually travel fartherin the rolling cycle than do conventional three-wheel road-rollers, andthus the general convenience achieved by our invention in turning themachine around in a short radius is of considerable value, although itmay be desired to retain the conventional reversible transmissiondisclosed in our co-pending application Serial No. 555,098 (Patent2,437,524) before mentioned. Our arrangement thus renders it possible toutilize the usual truck or tractor type transmission with completesatisfaction, due to better opportunity to turn the machine around andtravel in a forward direction of gear at all times. Furthermore, in ournovel tamping roller the driving rolls II precede and pull the trailingrolls 25, and hence the latter offer less rolling resistance than ifsame were pushed. Moreover,

fastener? 5. since the rolls 25 that are not driven are arranged astrailing rolls, a greater number of such; rolls 25 may be utilized. inthe assembly, thus: increasing the efliciency of the; tamping roller.

By the above construction the traction unit A is articulated forsteering. with respect to the trailing and supporting unit B. Thus thedriving rolls II are also the steering. rolls; however, each of therolls. H and 25 are mounted to oscillate freely in their sub-frames, 9and. 24- at. all times to follow the ground. contour. The use: of thehorizontal pivot bolt 34- on which the draw bar terminal 35 is pivotednot only allows oscillation of: the trailing unit B- with respect to thetraction unit A, but also relieves frame strains as well as permitstherollsto better follow the contour of the ground.

In Figs. 1-4 inclusive, the vertical king pin- 28 is disposed in rear ofthe axis! of axles ID of drive rolls ll of the traction unit A. But-inFigs. 5, 6, 7 a modification is shown in. which a traction unit A,trailing unit Bv and the pivotal connection C are utilized, the samebeing generally similar to ,7

those described in connection with the preceding Figures 1-4. However,in this modification the motor l is placed over the transmission 2 andover the differential 3, and in this arrangement the differential 3 andtransmission 2 are disposed forwardly of the arrangement shown in thepreceding figures to permit. the location of the vertical king pindirectly over and in line with the axis of the axles IQ. of the driverolls I I, thus providing correct steering from a geometricalstandpoint. when the machine is not traveling, such arrangement beingparticularly desirable when loading the roller on freight cars, orturning. in. tight places while at a standstill. In this arrangement thedrive shafts 3a project, from the differential housing 3' in front ofthe drive rolls I. 1' instead. of in rear thereof as in the precedingfigures. The arrangement of shaft and sprocket drive from thedifierential shaft sections 311 to drive the drive rolls I If, however;is otherwise the same as described in connection with. the precedingfigures, and similar parts. are similarly lettered and hence the driveneeds no detailed description herein, except to state that the bracketsM for supporting. the shafts i5 of the drive sprocket It are disposed atthe front outer ends rather than at the rear outer ends of the subframes 9; as in the, preceding figures, the drive rolls liybei'rigmounted in sub frames 9 pivoted on horizontal axes as in the precedingfigures.

In this modification. the trailing unit B is also. substantiallyidentical with the trailing unit shown in the preceding figures,, andhence needs no specific description herein. In this modification thecab" 5 shown in the preceding figures is omitted; however, it is obviousthat a cab may be provided above the operators seat 6, if desired.

Asabove stated, the pivotal connection C be tween the units A" and- H isdisposed above and line with the axis of the axles Hlof the drive rolls-F as shown Fig. 6, the pivotal connection being shownmore particularlyin Fig. 7. The king pin 28 carries a cap plate-3E5 secured by screws orbolts 3 I as in the preceding figures, the 111110 3 2 of the dlrawbarbeing confined between the bracket andcap plate 30: Hub 32 carriesahorizontal bolt 34 for the drawbar terminal 35 secured by a rigid frame43 to the front end of the trailing unit B, which unit is therebypermitted to: pivot with respect to the traction unit A on thehorizontal axis (bolt 34.) and vertical axis (-king pin 28) as inthepreceding figures.

' In tins modification the hub 32' of the drawba-r has rigidly secured;thereto a. bracket plate H (Figures 6, '7) normally projectingrearwardly and laterally with. respect tothe longitudinal axis: of thetam-ping roller, as shown irrFig. 6-. The outer end of the piston rod46- ispivotally connected as at 46a to the bracket. 54, while theopposite end of the. double. acting: cylinder 39 is pivotally connectedas at 3% to. a. bracket 4-5 (Fig; '2) carried by the chassis of tractionunit A" at the opposite side: of the longitudinal axis or'theframe'Afrom the pivot Alla, as clearly shown; in Fig; 6;. Thus by admission offluid under pressure to either end of cylinder 39 the piston; rod 4:0?will; beactuated to pivot the trailing unit B with respect to thetraction unitA.

The: operation of: the tamping rollershown in Figures 5, 6., 7. isidentical with that; shown in the preceding figures, but thearrangement; or the king pin 28 above the axis of the axles. l ii or thedriving rolls: Il1 permits easy steering. when the machine is nottraveling, which a desirable feature.

In Figures 8, 9, a further modification of the tamping roller is shownin. which the traction. unit A2 and the pivotal: connection. C2"between: the traction unit. A2. and. the: trailing unit B1 is.substantially identical withzthat shown in Figures 5, 6, '7. However, inthis modification; the frame of the trailing unit B21 consists. ofcrossmembers 58, 5! which are: connected at their outer end'sby parallelarched frame members. 52.. Trailing unit B2 carries three individuallypivoted: tamping rolls, the outer. tamping: rolls 53. being journaled insub-frames 54 in. a manner similar to the sub-frames 24' shown in:Figure 6;. the sub-frames being pivoted on horizontal pivots. Elia;atthe outer ends of the cross members. 59, 5'! preferably under thearched frame members 52. At the forward end of the frame of trailingunit B2 is a cross member 55 (Fig. 9) provided with horizontal pivotsfor the sub-frame 57 of the center roll 58 As shown in Fig. thehorizontal pivots for sub-frame 5? which carries center-roll sub-frame59 for center roll 56 consists of spaced perforated lugs 56a on crossmember 55 between which perforated lugs 5E on sub-frame 51' enter,pivot-pins? 56b passing through the registering perforations in the lugs5t-5Ea. In this: manner the center roll 53 can rise or lower verticallyto better followthe contour of the ground, the center roll innersub-frame 59 being journaled for Oscillation in sub-frame 51 at pivots60 in a manner similar to the sub-frames 5% in their pivots 54a.

The trailing unit 132 carries a rear extension B l which includes a ballsocket 63, and ball head 62 connects drawbar' E4. to a trailingsub-frame 65 of the trailing roll 66; the ball and socket con-- nectionpermitting independent universal oscilation of the sub-frame 65'carrying roll 66- a'nd hence a pivot in the sub-frame 65' is notnecessary in view of the ball and socket connection; Roll 66is-journaled in'itssub-frame 65 in a manner similar to the other rolls.

In this modification it will be noted that the addition of center roll58 of the trailing unit B2 and the final trailing. roll to constitutethe chi-eat difference-over the arrangement shown Figures 5, 6 and '7.The machine shown in Figures 8; 9 would therefore tam'p the full widthor the chine, and: two rolls would: pass over the entirearea beingtamped upon each passage of the machine. In Figs. 1-7 there isconsiderable-space between the drive rolls: of the traction units or Aand. between the rolls of thetrailingunits 1 B or B. The type shown inFigs. 8 Q better" lends itself to designs of large heavy tampingrollers.

Figs. 10 and 11 show a modification of the drive for the drive rolls Hof the traction unit, gear trains being utilized instead of the chainand sprocket drives disclosed in the preceding figures. For purposes ofillustration the gear train arrangement is shown in connection with thetamping roller construction shown in Figs. 1 to 3 inclusive. However, itis understood that the gear train drive may be obviously utilized inconnection with any of the remaining prior modifications in lieu of thechain and sprocket drive.

In Figs. 10 and 11 the main parts are similar to corresponding partsshown in Figs. 1 and 3, and similar parts are similarly numbered. Inthis modification, however, the drive roll Ii carries a gear 80, inplace of the chain sprocket l3 of Fig. 3, and the stub shaft l5 carriesa pinion 8| disposed in alignment with gear 83. An idler gear 82 isjournaled on a stub shaft 83 mounted in the adjacent side of the subframe 9, said gear 82 meshing with both gears 89 and 8| respectively, asclearly shown in Figs. and 11. However, two or more idler gears may beutilized in place of the single gear 82, if desired.

Since the shaft I5 is journaled in bracket it carried by the sub frame 9the same will remain at all times parallel with the axle is of the driveroll II for any tilting or swinging positions of the sub frame, andhence the gear train 86, 81 and 82 will constantly remain in propermeshing relation during swinging of the sub frame 9. Thus the gear traindrive shown in Figs. 10 and 11 may obviously be applied to themodifications shown in Figs. 1 to 4 inclusive, Figs. 5 to '7 inclusive,and Figs. 8 and 9 inclusive.

The platform or frames of the trailing units B and B are well adapted tocarry extra ballast, where desired. The roll diameters are unlimited byother elements of the machine such as the front roll mounting shown inour copending application Serial No. 555,098.

In each modification of machine shown by placing the driving rolls atthe front end of the tamping roller, a greater number of rolls can beutilized, because the rolls which are not driven will be pulled at alltimes and will therefore offer less rolling resistance than if they werepushed.

We do not limit our invention to the exact forms shown in the drawings,for obviously changes may be made therein within the scope of theclaims.

We claim:

1. A self-propelled roller, comprisin a, traction unit; a pair ofparallel drive rolls mounted in subframes carried by said unit onhorizontal pivots for oscillation on horizontal axes parallel with thelongitudinal axis of the traction unit; a motor in said unit actuating adifferential having laterally disposed shaft sections; devices actuatedby the shaft sections for driving the said drive rolls; a combinedtrailing and supporting unit; a rollmonnted in a sub-frame carriedbysaid trailing unit on horizontal pivots for oscillation on ahorizontal axis parallel with the longitudinal axis of the trailingunit; coupling means including a vertical pivot and a horizontal pivot,said means connecting the said units together on an axis extendingbetween said drive rolls, said connecting means permitting swinging ofthe units about a, vertical axis between the drive rolls and permittingrelative swivelling of the units about a horizontal axis; and means forswinging 8 the units about said vertical axis to effect steering.

2. In a roller as set forth in claim 1, said devices |comprisingtransversely disposed stub shafts journaled in brackets carried by thesubframes of the traction unit opposite the differential shaft sections;aligned sprockets carried by the drive rolls and stub shaftsrespectively; and chains running around the aligned sprockets fordriving the respective drive rolls.

3. In a roller as set forth in claim 1, said devices comprisingtransversely disposed stub shafts journaled in brackets carried by thesub frames of the traction unit opposite the differential shaftsections; aligned gears carried by the drive rolls and stub shaftsrespectively; and idler gears journaled in the sub frames meshing withsaid aligned gears.

4. In a roller as set forth in claim 1, said coupling means comprising avertical king pin carried by the traction unit in the vertical plane ofthe steering axles; a horizontal drawbar having a hub journaled on saidking pin; and a head swiveled on said drawbar and rigidly connected withthe trailing unit on the axis thereof.

5. In a roller as set forth in claim 1, said coupling means comprising avertical king pin carried by the traction unit in the vertical plane ofthe steering axles; a horizontal drawbar having a hub journaled on saidking pin; and a head swiveled on said drawbar and rigidly connected withthe trailing unit on the axis thereof; and said swinging meanscomprising a doubleacting hydraulic :cylinder having a piston rod anddisposed at an angle to the longitudinal axis of the roller, said pistonrod and opposite end of the cylinder pivotally connecting the drawbarand traction unit.

6. A self-propelled tamping roller, comprising a traction unit; a pairof parallel drive rolls carrying tamping elements and mounted in subframes carried by said unit on horizontal pivots for oscillation onhorizontal axes parallel with the longitudinal axis of the tractionunit; a motor in said unit actuating a differential having laterallydisposed shaft sections to serve as a drive means; flexible andelongatable shafting extending from said differential shaft sections toserve as a drive means; driven means actuated by the shafting fordriving the said drive rolls while permitting the rolls to oscillatefreely; a combined trailing and supporting unit; a roll carrying tampingelements and mounted in a sub frame carried by said trailing unit onhorizontal pivots for oscillation on a horizontal axis parallel with thelongitudinal axis of the trailing unit; coupling means including avertical pivot and a horizontal pivot, said means connecting said unitstogether on an axis extending between said drive rolls, said connectingmeans permitting swinging of the units about a vertical axis between thedrive rolls and permitting relative swiveling of the units about ahorizontal axis;

and means for swinging the units about said vertical axis to effectsteering.

7. In a tamping roller as set forth in claim 6, said driven meanscomprising transversely disposed stub shafts journaled in bracketscarried by the sub frames of the traction unit opposite the differentialshaft sections; aligned sprockets carried by the drive rolls and stubshafts respectively; chains running around the aligned sprockets fordriving the respective drive rolls; and said flexible and elongatableshafting comprising splined sectional shafts connected at their g endsby universal joints to the stub shafts and differential shaft sectionsrespectively.

8. In a tamping roller as set forth in claim 6, said driven meanscomprising transversely disposed stub shafts journaied in bracketscarried by the sub frames of the traction unit opposite the differentialshaft sections; aligned gears carried by the drive rolls and stub shaftsrespectively; idler gears journals d in the sub frames meshingwith saidaligned gears; and said flexible and elongatable shafting comprisingsplined sectional shafts connected at their ends by universal joints tothe stub shafts and differential shaft sections respectively.

'9. In a tamping roller as set forth in claim 6., said coupling meanscomprising a vertical king pin carried by the traction unit in thevertical plane of the steering axles; a horizontal drawbar having a hubjournaled on said king pin; and a head swiveled on said drawbar andrigidly connected with the trailing unit on the axis thereof.

10. In a tamping roller as set forth in claim 6, said coupling meanscomprising a vertical king pin carried. .by the traction unit in thevertical plane of the steering axles; a horizontal drawbar having a hubjournaled on said king pin; and a head swiveled on said drawbar andrigidly connected with the trailing unit on the axis thereof; and saidswinging means comprising a double-acting hydraulic cylinder having apiston rod andd-isposed at an angle to the longitudinal axis of theroller, said piston rod and opposite end of the cylinder pivotallyconnecting the drawbar and traction unit.

11. A self-propelled tamping roller, comprising a traction unit; a pairof parallel drive rolls carrying tamping elements and mounted in subframes carried by said unit on horizontal pivots for oscillation onhorizontal axes parallel with the longitudinal axis of the tractionunit; amotor in said unit actuating a differential having laterallydisposed shaft sections; flexible and elongatable shafting extendingfrom said differential shaft sections; driven means actuated by theshaf-tin-g for driving the said drive rolls while permitting the rollsto oscillate freely; a combined trailing and supporting unit; a secondpair of parallel rolls carrying tamping elements and mounted in subframes carried by said trailing unit on horizontal pivots foroscillation On horizontal axes parallel with the longitudinal axis ofthe trailing unit; coupling means including a horizontal pivot and avertical pivot, said means connecting the traction and trailing unitstogether on an axis extending between said drive rolls, said connectingmeans permitting swinging of the units about a vertical axis between thedrive rolls and permitting relative swiveling of the units about ahorizontal axis; and meansfor swinging the units about said verticalaxis to effect steering.

12. In a tamping roller as set forth in claim 11, said driven meanscomprising transversely disposed stub shafts iournaled in bracketscarried by the sub frames opposite the differential shaft sections;aligned sprockets carried by the drive rolls and stub shaftsrespectively; chains running around aligned sprockets for driving therespective drive rolls; and said flexible and elongatable shaftingcomprising splined sectional shafts connected at their ends by universalJoints to the stub shafts and differential shaft sections respectively.

13. In a tarnping roller as set forth in claim 11, said driven meanscomprising transversely disposed stub shafts journaled in bracketscarried by the sub frames of the traction unit opposite the differentialshaft sections; aligned gears carried by the drive rolls and stub shaftsrespectively; idler gears journaled in the sub frames meshing with saidaligned gears; and said flexible and elongatable shafting comprising"splined sectional shafts connected at their ends by universal joints tothe stub shafts and differential shaft sections respectively.

14. In a tamping roller as set forth in claim 11, said rolls of eachunit being spaced apart; and the rolls of the trailing unit trackingthose of the traction unit.

15. In a tamping roller as set forth in claim 11, said rolls of thetraction unit being spaced apart; and the rolls of the trailing unittracking those of the traction unit; an intermediate tamping rolljournaled in an intermediate sub frame disposed between the rolls of thetrailingunit; said intermediate sub frame being disposed on thelongitudinal axis of the trailing unit and mounted in horizontal pivotsfor oscillation on a horizontal axis; one end of the intermediate subframe being connected in the trailing unit to permit same to swingthereon on a horizontal axis transversely of the trailing unit; and athird tamping roll journaled in a third sub frame disposed in rear ofthe intermediate tamping roll;

said third sub frame being connected to the rear end of the trailingunit for universal swinging movement.

16. In a tamping roller as set forth in claim 11, said coupling meanscomprising a vertical king pin carried by the traction unit in thevertical plane of the steering axles; a horizontal drawbar having a hubjournaled on said king pin; and a head swiveled on said drawbar andrigidly connected with the trailing unit on the axis thereof.

17. In a tamping roller as set forth in claim 11, said coupling meanscomprising a vertical king pin carried by the traction unit in theVertical plane of the steering axles; a horizontal drawbar having a hubjournaled on said king pin; and a head swiveled on said drawbar and,rigidly connected with the trailing unit on the axis thereof; and saidswinging means comprising a double-acting hydraulic cylinder having apiston rod and disposed at an angle to the longitudinal axis of theroller, said piston rod and opposite end of the cylinder pivctallyconnecting the drawbar and traction unit.

18. A self propelled tamping roller, comprising a traction unit; a pairof parallel drive rolls carrying tamping elements and mounted in subframes carried by said unit on horizontal pivots for oscillation onhorizontal axes parallel with the longitudinal axis of the tractionunit; a motor in said unit actuating a differential having laterallydisposed shaft sections; said motor and differential being aligned andthe shaft sections of the differential being disposed adjacent the 3rear ends of the sub-frames; flexible and elongatable shafting extendingfrom said differential shaft sections; devices actuated by the shaftingfor driving the said drive rolls while permitting the rolls to oscillatefreely; a combined trailing and supporting unit; a second pair ofparallel rolls carrying tamping elements and mounted in sub framescarried by said trailing unit on horizontal pivots for oscillation onhorizontal axes parallel with the longitudinal axis of the trailingunit; coupling means including a vertical pivot and a horizontal pivot,said means connecting the traction and trailing units together on anaxis extending between said drive rolls, said connecting meanspermitting swinging of the units about a vertical axis between the driverolls and permitting relative swiveling of the units about a horizontalaxis; vertical pivot of the coupling being disposed in rear of the axlesof the drive rolls; and means for swinging the units about said verticalaxis to effect steering.

19. In a tampering roller as set forth in claim 18, said rolls of thetraction unit being spaced apart; and the rolls of the trailing unittracking those of the traction unit; an intermediate tamping rolljournaled in an intermediate sub frame disposed between the rolls of thetrailing units; said intermediate sub frame being disposed on thelongitudinal axis of the trailing unit for oscillation on a horizontalaxis; one end of the intermediate sub frame being connected in thetrailing unit to permit same to swing therein on a horizontal axistransversely of the trailing unit; and a third tamping roll journaled inathird sub-frame disposed in rear of the intermediate tamping roll; saidthird sub-frame being connected to the rear end of the trailing unit foruniversal swinging movement.

20. In a tamping roller as set forth in claim 18, said coupling meanscomprising a vertical king pin carried by the traction unit on the axisthereof; a horizontal drawbar having a hub journaled on said king pin;and a head swiveled on said drawbar and rigidly connected with thetrailing unit on the axis thereof; and said swineing means comprising adouble-acting hydraulic cylinder having a piston rod and disposed at anangle to the longitudinal axis of the roller, said piston rod and theopposite end of the cylinder pivotally connecting the drawbar andtraction unit.

21. A self-propelled tamping roller, comprising a traction unit; a pairof parallel drive rolls carrying tamping elements and mounted in subframes carried by said unit on horizontal pivots for oscillation onhorizontal axes parallel with the longitudinal axis of the tractionunit; a motor in said unit actuating a differential having laterallydisposed shaft sections; said motor being disposed above thedifferential with the shaft sections of the differential disposedadjacent the front ends of the sub frames; flexible and elongatableshafting extending from said differential shaft'sections; driven meansactuated by the shafting for driving the said drive rolls whilepermitting the rolls to oscillate freely; a combined trailing andsupporting unit; asecond pair of parallel rolls carrying tampingelements and mounted in sub frames carried by said trail- 12 ing uniton-horizontal pivots for oscillation on horizontal axes parallel withthe longitudinal axis of the trailing unit; coupling means including avertical pivot and a horizontal pivot, said means connecting thetraction and trailing units together on an axis extending between saiddrive rolls, said connecting means permitting swinging of the unitsabout a vertical axis between the drive rolls and permitting relativeswiveling of the units about a horizontal axis; said vertical pivot ofthe coupling unit being disposed directly above the axles of the driverolls; and means for swinging the units about said vertical axis toeffect steering.

22. In a tamping roller as set forth in claim 21, said rolls of thetraction unit being spaced apart; and the rolls of the trailing unittracking those of the traction unit; an intermediate tamping rolljournaled in an intermediate sub frame disposed between the rolls of thetrailing units; said intermediate sub frame being disposed on thelongitudinal axis of the trailing unit for oscillation on a horizontalaxis; one end of the intermediate sub frame being connected in thetrailing unit to permit same to swing therein on a horizontal aXistransversely of the trailing unit; and a third tamping roll journaled ina third sub frame disposed in rear of the intermediate tamping roll;said third sub frame being connected to the rear end of the trailingunit for universal swinging movement.

23. In a tamping roller as set forth in claim 21, said coupling meanscomprising a vertical king pin carried by the traction unit on the axisthereof; a horizontal drawbar having a hub journaled on said king pin;and a head swiveled on said drawbar and rigidly connected with thetrailing unit on the axis thereof; and said swinging means comprising adouble-acting hydraulic cylinder having a piston rod and disposed at anangle t the longitudinal axis of the roller, said piston rod and theopposite end of the cylinder pivotally connecting the drawbar andtraction unit.

CARL F. GREINER. J OHN F. HARRISON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,226,182 Ross Dec. 24, 19402,230,317 Zettelmeyer Feb. 4, 1941 2,272,619 Flynn Feb. 10, 19422,303,336 Day Dec. 1, 1942 2,362,262 French Nov. '7, 1944

